From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B5DFB606A324 for ; Tue, 3 Nov 2026 14:02:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=k1lXTOrj; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=YwBrmiMc DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=aoEz3XDvNbQleGg7AGotOLvdqQR5gJ3dWjYehkJVEAg=; b=k1lXTOrjg7fdw5sTpqf02R6Shq 3YLVn/eoFwJstfRxqRgFQoJDGJbAQFyCkEGVbZvHJe63EWMWXm5QuRulEeyWl8XIm4wEavBpRS7tQ RhYJfwlbGwpSOtKogjtMcE9CQanX/Zz9J52Anf2INTC6oUgS7iKEGyvt1GiRWsvRy9cGmdUraBzMH RiW2zh6/Cea1c+aRLlaFNx6KrkFmXn/9NW81CheTLvOMSrTvNbMvZcV9nwCwdVaUuw8vBlKsFxSee ZtLj0dpVGxIQqvCcipKySDF4xYfSWLGbXh2eGbEaXERrLR58rg2OOC3zx+CQdf2qkAwYomR9qYEaE 2HBU4O1g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOF5D-00000002fZu-3BIc; Tue, 03 Nov 2026 14:01:51 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOF59-00000002fYH-3nht for linux-arm-kernel@lists.infradead.org; Tue, 03 Nov 2026 14:01:50 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4989C1595; Tue, 3 Nov 2026 06:01:40 -0800 (PST) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 32A593F673; Tue, 3 Nov 2026 06:01:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793714503; bh=wIZLjMr9MrBhBElX8/30eyxmo0F41I4lrfTa+wBa7tQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YwBrmiMcxgxgc/oqB40Ht/y8m8LlWct0YtdnpHGGvzDuec16EtV7NY+oHv/hCetja 2f6zsYjxlTcIoz6eOMhAtSEfc75BbV73NZgTZSmw9FZPhcLeJhcnrlIilEq0T1jk4E 8CZPmtRTgv3jpFSsvkXhvGT+Q5XvXx7Avzo3Mwb8= Date: Tue, 3 Nov 2026 14:01:38 +0000 From: Catalin Marinas To: Kameron Carr Cc: decui@microsoft.com, haiyangz@microsoft.com, mhklinux@outlook.com, wei.liu@kernel.org, arnd@arndb.de, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, lpieralisi@kernel.org, mark.rutland@arm.com, sudeep.holla@kernel.org, thuth@redhat.com, will@kernel.org Subject: Re: [PATCH v6 2/6] arm64: hyperv: Detect Hyper-V via RSI host call in CCA Realms Message-ID: References: <20261031001412.4150488-1-kameroncarr@linux.microsoft.com> <20261031001412.4150488-3-kameroncarr@linux.microsoft.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261103_060148_936747_36D03F05 X-CRM114-Status: GOOD ( 20.60 ) X-Spam-Score: -4.4 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon, Nov 02, 2026 at 11:27:37AM -0800, Kameron Carr wrote: > On 11/2/2026 4:12 AM, Catalin Marinas wrote: > > On Fri, Oct 30, 2026 at 05:14:08PM -0700, Kameron Carr wrote: > >> When booting without ACPI, hyperv_detect_via_smccc() detects Hyper-V by > >> querying the SMCCC vendor hypervisor UID. In an Arm CCA Realm the SMCCC > >> call is handled by the RMM rather than by the hypervisor, so the > >> query never reaches Hyper-V and detection fails. > >> > >> When running in a Realm, forward ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID > >> to the host with RSI_HOST_CALL instead, which is how Hyper-V hypercalls > >> are issued from a Realm. > >> > >> This is done in the Hyper-V code rather than in the generic > >> arm_smccc_hypervisor_has_uuid() because the other users expect different > >> behavior. > >> > >> hyperv_init() is an early_initcall and runs before the secondary CPUs > >> are brought up, so a single __initdata host call structure is used > >> without locking. > >> > >> ACPI-based detection and non-Realm guests are unaffected. > >> > >> Signed-off-by: Kameron Carr > > > > This works for me, thanks. I replied to Dexuan clarifying my objection > > to v5 do the UUID check generically. > > Thank you for your review and suggestions. > Your clarification makes sense. > > Is this a "Reviewed-by" or an "Acked-by"? I don't usually ack the hyperv patches as I don't know enough about it but given that I commented on this particular patch in v5: Reviewed-by: Catalin Marinas -- Catalin